Strand plying method and apparatus

ABSTRACT

A CORD FORMING METHOD AND APPARATUS, THE APPARATUS INCLUDING A SKIP TYPE STRANDING SPINDLE EMPLOYING A BALLOON GENERATING DISC AND AN IDLER FLYER, THE IDLER FLYER BEING SO DISPOSED THAT THE PORTION OF THE BALLOON FORMED BETWEEN THE IDLE FLYER AND THE BALLOON APEX ALWAYS ROTATES IN THE FIRST QUADRANT. THE BALLOON IS MAINTAINED UNDER CONTROL BY MEANS RESPONSIVE TO CHANGES IN TENSIN OF THE SINGLES STRAND IN THE BALLOON, SUCH MEANS VARY THE TENSION AND SPEED AT WHICH THE PLIED STRAND OR CORD IS WITHDRAWN FROM THE PLYING POINT OF THE SPINDLE.

Sept. 20, 1971 w VIBBER 3,605,394

STRAND FLYING METHOD AND APPARATUS Filed Aug. 8, 1969 INVENTOR.

United States Patent thee Patented Sept. 20, 1971 3,605,394 STRAND PLYING METHOD AND APPARATUS Alfred W. Vibber, 350 th Ave., Suite 6314, New York, N.Y. 10001 Filed Aug. 8, 1969, Ser. No. 848,491 Int. Cl. D01l1 7/86; D02g 3/00 US. Cl. 57-58.3 14 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a method of and an apparatus for plying strands to form cords.

The present invention is an improvement upon and a simplification of that shown and claimed in my patent No. 3,307,342.

The invention has among its objects the provision of a novel skip type stranding spindle and method.

Another object of the invention is the provision of a spindle and method of the type above indicated for controlling the balloon by the tension of the ballooning singles strand.

A further object of the invention is the provision of a spindle and method wherein the pull exerted on the plied strand to withdraw it from the plying point is 'varied in accordance with tension variations in the run of the outer, ballooning singles strand approaching the plying point.

The above and further objects and novel features of the invention will more fully appear from the following description when the same is read in connection with the accompanying drawings. It is to be understood, however, that the drawings are for the purpose of illustration only, and are not intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views:

FIG. 1 is a view in elevation illustrating a preferred embodiment of strand plying apparatus in accordance with the invention;

FIG. 2 is a fragmentary view in vertical axial section through the lower end portion of the spindle of FIG. 1;

FIG. 3 is a view in side elevation of the capstan which withdraws cord from the plying point of the spindle; and

FIG. 4 is a schematic view showing a portion of an outer, ballooning singles strand, the inner strand, and the cord formed at the plying point of the spindle, the view showing in full lines and in an exaggerated manner the composite run of cord and inner strand under a normal condition, and in dot-dash lines the composite run of the inner singles strand and the cord when it is subjected to the tension of a balloon under increased tension.

Referring now to the drawings, and first particularly to FIG. 1, there is shown a spindle, generally designated 10, for plying two strands together to form a cord. Such cord is useful, for example, as a reinforcement in automobile tires and V-belts. The spindle shown is of the skip type, performing a strand-wrapping operation which adds no twist to the respective strands. The spindle is supported on a frame which is partially shown in FIG. 1, which comprises a support having a longitudinally extending beam 11. A post 12 extends upwardly from the beam 11 and carries on its upper end an overarm 14 having a bracket 15 with a guide pulley 16 thereon.

An outer strand package 17 is supported on a bracket which extends upwardly from the frame of the machine, the bracket rotatably supporting a holder for the package 17. The support for the package 17 carries a cage about the package, such cage mounting a guide pulley (not shown) for guiding the strand a from package 17 as such strand is delivered toward the cord-forming point or plying junction P. From such guide pulley, the strand a is led to a metering capstan 18, the strand being wound several times about an outer pair of driven strand metering rollers 19 and 20 which pull the strand a from the package 17 at a controlled rate. In the illustrative embodiment, rollers 19 and 20 are driven from the main, hollow shaft 21 of the spindle 10 through the medium of gearing which is not here shown but which is shown and described in my patent, No. 2,857,730. Shaft 21 is driven by a motor (not shown) through the medium of a belt 22 which is entrained over a pulley 24 on shaft 21.

From the metering rollers 19 and 20, strand a is led about a first fixed pulley 25 and thence upwardly to a second fixed pulley 26 from which it travels to the above mentioned pulley 16. Pulley 16 has its strand-delivering surface tangential to the central axis of the inner strand package 23 and above the central axis of the loop or balloon 27 formed in the strand a by rotation of the shaft 21 and of the flier disc 29 secured thereto.

From the pulley 16, the strand a passes downwardly through a hollow shaft or spindle 30, which carries a strand guide 31 at its lower end. Preferably, shaft 30 is adjustably mounted on overarm 14, being held in adjusted position by a lock nut 32. Upon leaving the guide 31, strand a passes into its loop or balloon 27 and thence past the inner package 23 and through a guide eyelet 33 fixed in the outer periphery of the flier disc 29. As shaft 21 is rotated, the flier disc 29 and the guide eyelet therein rotate the strand a between the flier and the guide 31 above the inner package to form the described loop or balloon 27 in the yarn about the inner package 23.

The inner package 23 is mounted on a member 34 which is rotatably supported on shaft 21. Strand b is led from the package 23 to a first fixed pulley 35, a floating pulley 36, and a second pulley 37, to be fed to an inner metering capstan 38 having laterally spaced inner metering rolls 39 and 40 which advance the strand b to a canted pulley 41 to be directed downwardly through the center of the hollow rotating shaft 21. Rolls 39 and 40 are joumalled in the supporting member 34. As shown in FIG. 1, roll 39 is positively driven from shaft 21 by means of a worm secured to the shaft and a meshing worm gear on the shaft carrying roll 39. Roll 40 is idle. The strand metering means 38 made up of rolls 39 and 40, as is also the case of the metering means 18 made up of rollers 19 and 20, is driven in synchronism with shaft 21; means 18 and 38 tend to forward their respective strands at substantially constant speed.

The two strands, strand a passing radially inwardly from its loop or balloon 27, and strand b passing generally axially of shaft 21, meet at the plying junction or point P and are united within the shaft 21. The resulting plied cord 0 thus formed is pulled downwardly out of the rotating shaft 21 to be wound on a take-up package generally shown at 42. The speed of pulling of the cord 0 away from the plying junction P is governed by a variable speed take-up mechanism to be described, the strand pulling effect of such mechanism being responsive to variations in the tension of the strand a in the balloon.

Means are provided to prevent the supporting structure 34 for the metering rolls 39 and 40 and their appurtenant mechanism from rotating as the shaft 21 is rotated. Thus cooperating magnets 44 and 45, positioned respectively on member 34 and on fixed structure outside of the loop or balloon formed by the strand a, function to maintain the mechanism 34 in a fixed position in space.

In the embodiment shown in FIG. 1, there is provided an idle auxiliary flier, generally designated 45, similar to that designated 130 in applicants Pat. No. 3,153,893. Such auxiliary flier has a radial arm 46 with a guiding eye 47 at its outer end, eye 47 guidingly receiving the strand a at a location intermediate the height of balloon 27. The auxiliary flier has a central body portion 49 which is rotatably mounted in a bearing means 50 secured to a lid '51 of a protective shell member 52 which surrounds the inner strand package 23. Member 52 is supported on package support 34, as shown.

After the strands a and b have been twisted together at the plying point P, the plied strand or cord travels downwardly within the hollow shaft 21, emerging therefrom and traveling under and partially about a lower guide pulley 53 and thus to a cord take-up capstan 54. For reasons to be explained, the strand delivering portion of the surface of canted pulley 41 and the strand receiving portion of the surface of pulley 53 are disposed to guide the strand b and the cord 0, respectively, along the axis of the hollow main shaft 21 of the spindle. The capstan 54 delivers the cord to the above-mentioned cord takeup package 42. Such package may take the form of a bobbin which is supported by rolls 55, 56, and is forcibly but yieldingly held downwardly upon such rolls by hold down means (not shown) such as that shown in FIGS. 8 and 9 of my Pat. No. 3,336,740. The bobbin 42 is surface driven by at least one of rolls 55, 56, in the embodiment shown there being a constant speed geared motor 57 which is connected to roll 56 by a slip clutch 58. The speed of the motor 57 is such that its output shaft rotates at a speed somewhat above that required to drive the bobbin 42 to take up the cord. The cord is accordingly subjected to substantially constant tension at all times in the run thereof extending between the capstan 54 and the bobbin 42.

The capstan 54 has a driven roll 59 and an idle roll 60; the roll 59 is driven from the main, hollow shaft 21 of the spindle through the medium of a worm on shaft 21 and a worm gear meshing therewith on the shaft 61 on which roll 59 is aflixed. Since the worm and worm gear are conventional, they are not shown. The roll has a first, circular cylindrical part 62 disposed close to the sup porting beam 11 for the spindle. Outwardly of part 62 the roll 59 has a broad groove 63 the axially inner end of which is a frusto-conical surface 64 the larger end of which has the diameter of part 62 of the roll 59 and the smaller end of which has the diameter of an axially outer smaller diameter circular cylindrical part '65. The axially outer end of groove 63 is bounded by a transverse annular shoulder 66. The apex angle of frusto-conical surface 64 in the embodiment shown is 90, although it may be varied within limits depending upon the tension which it is desired normally to impose upon the run of the cord extending from the plying point to the capstan 54.

The cord 0 upon leaving the plying point and passing partially about guide pulley 53 passes upwardly to engage the capstan 54. The cord first engages the frustoconical surface 64 intermediate its axial length, and then covers the lower portion of surface 64 and the smaller diameter circular cylindrical part 65 of the roll 59 in a series of tightly engaging turns; from the last turn, which engages the shoulder 66, the cord passes sequentially to the circular cylindrical surface 67 of idle roll 60, to the large outer circular cylindrical portion 69 of roll 59, then again partially about roll 60, and finally to bobbin 42, as above described.

In the embodiment shown, employing the auxiliary flier which causes the portion of the balloon thereabove to rotate in the first quadrant at all times, when the effective diameter of the loop or balloon increases, the tension in the strand a therein also increases, and when the effective diameter of the loop or balloon decreases, the tension in the strand a therein also decreases. Such relationships are employed in controlling the balloon in accordance with the invention.

As above described, capstans 18 and 38 deliver the strands a and b at substantially the same speed. The cord take-up capstan 54 is so constructed and is driven at such speed as to subject the composite run of the inner singles strand from capstan 38 to the plying point P and the cord 0 from the plying point to the take-up capstan 54 to a high tension which is limited by the slipping of the cord upon the surfaces '64 and 65 of the take-up capstan roll 54. The high tension to which such composite run of strand b and cord 0 is subjected is such that the tension in the substantially radial run of the strand a leading from the balloon to the plying point, although deflecting the composite run radially outwardly of the axis of spindle shaft 21 at the plying point, is insuflicient to deflect the plying point enough for it to touch the inner wall of the shaft 21 at any time during the normal operation of the spindle.

It will be apparent from the above that the tension in the composite run b-c greatly exceeds that of the strand a in the balloon and in the generally radial run thereof extending to the plying point. It will also be apparent that a relatively small variation in the tension of strand a in such zone produces a large change in the tension of the composite run b-c. A change of tension in the composite run changes the speed at which capstan 54 takes up the cord, the cord engaging surfaces 64, 65 of capstan roll 59 more forcibly when the tension in the composite run increases. The cord forwarding speed of capstan 54 increases when the tension in the cord engaging it increases, and decreases when the tension in such cord decreases. This follows from the changes in slippage between the turns of cord and surfaces 64, 65 of capstan roll 59, and also from the fact that the diameter of the first turn of the cord on surface 64 of roll 59 tends to become larger by climbing the frusto-conical surface 64 when the turns of cord on roll 59 engage it more forcibly, and to become of smaller diameter when the ten sion of the cord engaging roll 59 decreases. The tension of strand a in the balloon thus serves, through the medium of its effect upon the composite strand run b-c, as a sensitive control of the cord withdrawing speed of the capstan 54-.

The speed and tension under which the cord 0 is withdrawn from the plying point P determine the diameter and thus the tension of the strand a in the balloon. When the cord is withdrawn from the plying point at an increased speed, the strand a tends to be withdrawn from the balloon at a greater speed than that at which it is fed into the balloon simply because strand a is a part of the cord c being taken up by the capstan 54. The reverse effect occurs when the cord is withdrawn from the plying point at a decreased speed.

The fact that the singles strands a and b are presented to the plying point at markedly different tensions does not prevent the resulting cord 0 from containing substantially equal lengths of the two strands. The metering capstans 18 and 38 forward singles strands a and b, respectively, at substantially the same speeds at all times. If the cord forming system is to be stable, the lengths of the two singles strands forwarded by their capstans 18, 3-8 must be continually absorbed in the resulting cord.

It appears, although applicant does not wish to be bound by such theory, that Well before the cord has reached the capstan 54 the tensions in the two strands a and b have become equal, each strand then assuming one-half of the total tension upon the composite run b-c. Such equal division of the tension also tends to cause the cord as finally taken up by capstan 54 and wound upon bobbin 42 to contain equal lengths of the two singles strands.

As above described, as the strands a and b immediately approach the plying point P the tension in strand b very greatly exceeds the tension in strand a, the strand b at such point P sustaining practically the full tension (minus the longitudinal force component of the tension of strand a in the balloon) to which the cord is subjected beyond the plying point. As more and more turns of the two sin gles strand are twisted together, and the length of frictional contact between the strands increases, strand a is subjected to more and more tension until it assumes its full share of the total tension. During such brief period, the strands a and b adjust themselves into the position which they finally assume in the finished cord.

I claim:

1. A method of plying two strands by twisting them about each other, comprising feeding forwardly at one zone a first strand from a source of supply of such strand and extending the thus fed first strand from said zone in a first run extending between two successive longitudinally spaced guides disposed forwardly of the zone of feeding of the strand, feeding a second strand into a rotating loop coaxial of said first run about the source of supply of the first strand, the loop being of such character that the tension of the strand in the loop increases when the diameter of the loop increases and decreases when the diameter of the loop decreases, leading the second strand out of the loop in a second run which extends generally radially of the first run to a plying point intermediate the length of the first run and which is free for appreciable deflection in a direction radially of the first run by variations in tension in the second strand in the loop, pulling the cord away from the plying point, and varying such pulling of the cord in response to variations of the radial deflection of the plying point.

2. A method according to claim 1, wherein the loop is created by a driven flier and has an apex remote from the flier, and the second strand enters the loop through the apex thereof, and wherein the strand-entering end of the loop always rotates in the first quadrant.

3. A method according to claim 1, wherein the cord is pulled away from the plying point by having frictional contact with a driven moving surface, and wherein the pulling of the cord is varied by varying the force with which the cord engages the driven moving surface.

4. A method according to claim 3, wherein the sidewise deflection of the first run tightens the cord against the driven moving surface, thereby to pull the cord under greater tension and at greater speed.

5. A method according to claim 1, wherein the first strand is fed at substantially constant speed from its source of supply into the first run.

6. A method according to claim 5, wherein the second strand is fed at substantially constant speed into the loop.

7. A method according to claim 1, wherein the tensions at the plying point in the first strand, the second strand, and the cord are in equilibrium.

8. Apparatus for plying two strands by twisting them about each other, comprising means for feeding forwardly at one zone a first strand from a source of supply of such strand, means for extending the thus fed first strand from said zone in a first run comprising two successive longitudinally spaced guides for the first run disposed forwardly of the zone of feeding of the strand, means for feeding a second strand into and rotating a loop thereof coaxial of said first run about the source of supply of the first strand, the loop being of such character that the tension of the strand in the loop increases when the diameter of the loop increases and decreases when the diameter of the loop decreases, means for leading the second strand out of the loop in a second run which extends generally radially of the first run to a plying point intermediate the length of the first run and which is free for appreciable deflection in a direction radially of the first run by variations in tension in the second strand in the loop, and means for pulling the cord away from the plying point and varying such pulling of the cord in response to variations of the radial deflection of the plying point.

9. Apparatus according to claim 8, wherein the tensions at the plying point in the first strand, the second strand, and the cord are in equilibrium.

10. Apparatus according to claim 8, comprising a driven flier for creating and maintaining the loop, an apex guide for the loop remote from the flier, and means for confining the apex end of the loop to rotation in the first quadrant.

11. Apparatus according to claim 10, wherein the means for feeding the second strand into the loop feeds it into the apex end of the loop.

12. Apparatus according to claim 8, wherein the means for pulling the cord away from the plying point comprises means having a driven moving surface, and wherein the pulling of the cord is varied by varying the force with which the cord engages the driven moving surface.

13. Apparatus according to claim 12, wherein the sidewise defiection of the first run tightens the cord against the driven moving surface, thereby to pull the cord under greater tension and at greater speed.

14-. Apparatus according to claim -13, wherein the means for pulling the cord away from the plying point comprises a driven capstan roll having a broad annular grove therein, said groove having a first, circular cylindrical root surface and a second frusto-conical surface, the second surface merging with the root surface at the smaller diameter of the second surface, and means for directing the cord into initial contact with the second surface intermediate its length, the cord thereafter being wound in a plurality of successive turns about and down the second surface and about the first surface.

References Cited UNITED STATES PATENTS Re. 24,3 10/1957 Vibber 5758.3 2,869,313 1/1959 Vibber 57--58.3 3,153,893 10/1964 Vibber 57--58.3 3,286,450 11/1966 Vibber 5758.3 3,290,873 12/1966 Vibber 5758.3 3,307,342 3/1967 Vibber 5758.3 3,499,277 3/ 1970 Vibber 57-58.3

DONALD WATKINS, Primary Examiner US. Cl. X.R. 57-160 

